Display screen or portion thereof with transitional graphical user interface



FIG. 1 is a front view of a first image of a display screen or portionthereof with transitional graphical user interface showing our newdesign;

FIG. 2 is a second image thereof;

FIG. 3 is a third image thereof;

FIG. 4 is a fourth image thereof; and,

FIG. 5 is a fifth image thereof.

The appearance of the transitional graphical user interface sequentiallytransitions between the images shown in FIGS. 1-5. The process or periodin which one image transitions to another image forms no part of theclaimed design.

The outer broken line in the figures illustrates a display screen orportion thereof and forms no part of the claimed design. The remainderof the broken lines in the figures illustrate portions of the graphicaluser interface and form no part of the claimed design.

CLAIM We claim the ornamental design for a display screen or portionthereof with transitional graphical user interface, as shown anddescribed.